The purpose of this paper is to study the effects on electromagnetic field levels of the green cell breathing technique in mobile networks. Although a great number of papers (including ours, see below) dedicated to QoS, radio issues and energy savings of the cell breathing algorithms have already been proposed, to the best of our knowledge, none has analyzed the effect on electromagnetic radiation. Yet, when cell sizes are changed (and specifically increase), it is evident that in some cases, the transmitted or received powers increase. We analyze the problem taking into account the different electromagnetic fields legal requirements and then estimate the received electric field for different cellular scenarios for LTE: a macro-only scenario, a macro scenario with cell-breathing and then a hybrid approach (femto/macro) combined with cell-breathing. Our simulation results show that given a number of radiation measurement sample points in a coverage zone, the percentage of threshold violations is exceeded by cell breathing. This occurs when more exigent levels to those given in the ICNIRP recommendations are taken.